Background The cytogenomic study of repetitive regions is fundamental for the understanding of morphofunctional mechanisms and genome evolution. Passiflora edulis a species of relevant agronomic value, this work had its genome sequenced by next generation sequencing and bioinformatics analysis performed by RepeatExplorer pipeline. The clusters allowed the identification and characterization of repetitive elements (predominant contributors to most plant genomes). The aim of this study was to identify, characterize and map the repetitive DNA of P. edulis , providing important cytogenomic markers, especially sequences associated with the centromere. Results Three clusters of satellite DNAs (69, 118 and 207) and seven clusters of Long Terminal Repeat (LTR) retrotransposons of the superfamilies Ty1/Copy and Ty3/Gypsy and families Angela, Athila, Chromovirus and Maximus-Sire (6, 11, 36, 43, 86, 94 and 135) were characterized and analyzed. The chromosome mapping of satellite DNAs showed two hybridization sites co-located in the 5S rDNA region (PeSat_1), subterminal hybridizations (PeSat_3) and hybridization in four sites, co-located in the 45S rDNA region (PeSat_2). Most of the retroelements hybridizations showed signals scattered in the chromosomes, diverging in abundance, and only the cluster 6 presented pericentromeric regions marking. No satellite DNAs and retroelement associated with centromere was observed. Conclusion P. edulis has a highly repetitive genome, with the predominance of Ty3/Gypsy LTR retrotransposon. The satellite DNAs and LTR retrotransposon characterized are promising markers for investigation of the evolutionary patterns and genetic distinction of species and hybrids of Passiflora .

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ABSTRACT. The genomic in situ hybridization (GISH) technique was applied to Passiflora interspecific F 1 HD13-133 hybrids (Passiflora sublanceolata x Passiflora foetida) and HD15-101 (Passiflora gardineri x Passiflora gibertii), and the backcrossed hybrids (BC 1 ) HD18-106 and HD18-113 (Passiflora sublanceolata x HD13-133). GISH was performed using genomic probes prepared with the DNA from the paternal genitor, whereas the maternal DNA was used as blocking DNA and employed at various concentrations (20X, 40X, 60X, and 100X) in relation to the probe concentration. At the same time, GISH was applied with the use of simultaneous probes from both genomes, paternal and maternal, that were detected with avidin-FITC and antidigoxigenin-rhodamine, respectively. Both methodologies allowed the distinguishing of the maternal and paternal genomes, thus confirming the hybrid nature of all the analyzed genotypes. Furthermore, the presence of recombinant chromosomes in BC 1 hybrids revealed the occurrence of meiotic recombination in HD13 hybrids. This application 2177 ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (1): 2176-2188 (2015 GISH technique for Passiflora of the GISH technique is an important step towards genomic analyses of Passiflora hybrids: it can broaden the phylogenetic and evolutionary studies of the genus and, at the same time, contribute to breeding programs.

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Genetic variation among accessions of the genus Manihot by ISSR markersAbstract -The objective of this work was to evaluate the genetic diversity within and among accessions of Manihot by using ISSR markers. Five species and two varieties of Manihot, besides two species of the genus Croton, used as the out-group, were analyzed by using 20 oligonucleotide (Olii) ISSR UBC primers. To analyze the similarity index between species and accessions, the Jaccard and simple matching coefficients were used. The 20 Olii tested were highly polymorphic in all species analyzed, and 89.7% of the loci were polymorphic. A higher genetic variability is observed among different species of Manihot, such as M. dichotoma var. undulata and M. caerulescens, than among individuals of the same species, such as M. dichotoma and M. dichotoma var. undulata.

ABSTRACT. Inter simple sequence repeat (ISSR) molecular markers were developed and used to investigate interspecific genetic variation in 25 wild species of Passiflora preserved in an active germplasm bank (BAG-Passifloras); intraspecific diversity was also analyzed in P. cincinnata accessions. Of 31 primers tested, 20 identified polymorphic loci with a total of 331 bands, suggesting high polymorphism in the sample. Interspecific polymorphism was greater than intraspecific polymorphism. This is a common finding in studies of genetic variation using dominant markers. The ISSRs revealed species-specific amplification bands in 11 species; these bands ranged from 200 to 1000 bp, and they will be of use for developing SCAR markers for the identification of germplasm in further studies. The use of Jaccard's similarity coefficient to obtain a dendrogram by the UPGMA clustering method distributed the taxa into five major groups, with differences among grouping with respect to 18535 ISSR application in wild Passiflora ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (4): 18534-18545 (2015) principal coordinate analysis. Despite the high cophenetic correlation coefficient (r = 0.94) of the dendrogram, taxonomic inconsistencies were observed; similar irregularities have been reported previously in studies using dominant markers. Intraspecific analysis of P. cincinnata accessions revealed a larger genetic distance between those from Bahia (P2) and from Minas Gerais (P2), indicating that both accessions have considerable potential as parents in a genetic improvement program for this species.

ABSTRACT. The analysis of meiotic behavior has been widely used in the study of plants as they provide relevant information about the viability of a species. Meiosis boasts a host of highly conserved events and changes in genes that control these events will give rise to irregularities that can alter the normal course of meiosis and may lead to complete sterility of the plant. The recombination of genes that occur in meiosis is an important event to generate variability and has been important in studies for genetic improvement and to create viable hybrids. The use of fluorescence in situ hybridization and genomic in situ hybridization (GISH) in meiosis allows the localization of specific regions, enables to differentiate genomes in a hybrid, permits to observe the pairing of homoeologous chromosomes, and if there was a recombination between the genomes of progenitor species. Furthermore, the GISH allows us to observe the close relationship between the species involved. This article aims to report over meiosis studies on plants and hybrids, the use and importance of molecular cytogenetic in meiotic analysis and contributions of meiotic analysis in breeding programs.

BackgroundA great interest exists in the production of hybrid plants of the genus Passiflora given the beauty and exotic features of its flowers which have ornamental value. Hybrid paternity confirmation is therefore important for assuring germplasm origin, and is typically carried out by molecular marker segregation. The aim of this study was to karyotypically characterize the chromosome heritance patterns of the progeny resultant from a cross of P. gardneri and P. gibertii using classical cytogenetics, chromosome banding, and molecular cytogenetics.ResultsAll analyzed genotypes showed the same diploid chromosome number as the genitor species: 2n = 18. Classical and CMA3 and DAPI staining allowed for chromosome counting and satellite identification (secondary constrictions). Fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) were used to characterize subgenomes by either identifying rDNA-specific genome patterns or parental genomes, respectively.ConclusionsThe heritance of chromosomal markers presenting rDNA sites from each parent for genome identification confirmed that all obtained plants were hybrids. These results will improve breeding programs involving the species of this genus. Apart from confirming hybridization, GISH allowed the visualization of recombination between the homeologous chromosome and the introgression of sequences of interest.Electronic supplementary materialThe online version of this article (10.1186/s12863-018-0612-0) contains supplementary material, which is available to authorized users.